Euphorbia milii plant named ‘Atlas’

ABSTRACT

A new distinct cultivar of  Euphorbia milii  plant named ‘Atlas’, particularly characterized by its compact plant habit; very dense and bushy plant form; moderate growth habit; abundant, large floral cymes with yellow-white bracts and red margins.

Genus and species of the plant claimed: Euphorbia lophogona×E. milii.

Variety denomination: ‘Atlas’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar ofEuphorbia plant, botanically known as Euphorbia lophogona×E. milii,commonly known as Crown of Thorns and hereinafter referred to by thename ‘Atlas’.

The new Euphorbia is a product of a planned breeding program conductedin Haarslev, Fyn, Denmark. The new Euphorbia milii originated from across made in 2001 by the Inventor, Steen Thomsen, with unnamedcultivars of Euphorbia. The male parent is an unnamed seedling ofEuphorbia milii Desmoul. and female parent is an unnamed seedling ofEuphorbia lophogona. The Inventor selected the new Euphorbia cultivar asa single plant from the progeny of the above crossing in 2001 on thebasis of its flower color and compact, freely branching habit. Plants ofthe new Euphorbia are upright, compact and have a unique color andabundant medium sized flowers.

Asexual reproduction of the new cultivar by terminal cuttings taken andpropagated and trial production batches at Hjortebjerg Nurseries,Denmark, has shown that the unique features of this new Euphorbia arestable and reproduced true to type in many successive generations ofasexual reproduction.

BRIEF DESCRIPTION OF THE INVENTION

Plants of the cultivar ‘Atlas’ have not been observed under all possibleenvironmental conditions. The phenotype may vary somewhat withvariations in environment such as temperature, light intensity, daylength, and fertility level without, however, any variance in genotype.

The following traits have been repeatedly observed and are determined tobe the unique characteristics of ‘Atlas’. These characteristics incombination distinguish ‘Atlas’ as a new and distinct cultivar:

1. Floral colors: Bracts from 158B, yellow-white to 149D yellow-greenwith red margins.

2. Very dense and bushy plant form.

3. Moderately vigorous, cylindrical growth habit; compact plant habit.

4. High number of flowers per plant borne on long gray-orange peduncles177A.

Plants of the cultivar ‘Atlas’ can be compared to plants of the cultivarEuphorbia milii. ‘Themis’ (unpatented). Side-by-side comparisonsconducted by the Inventor in Haarslev, Denmark, of the cultivar ‘Atlas’and the cultivar ‘Themis’ have shown they differ in the followingcharacteristics:

1. Plants of the new Euphorbia have striking red color and staminatecyathia with green, red bordered glands.

2. Plants of the new Euphorbia have smaller dark green leaves than‘Themis’.

3. Plants of the new Euphorbia have longer and stiffer peduncles thanplants of the cultivar ‘Themis’.

4. Plants of the new Euphorbia are more compact than the plants of thecultivar ‘Themis’.

5. Plants of the new Euphorbia have more flowers per plant than theplants of the cultivar ‘Themis’.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying color photographic drawings illustrate the overallappearance and details of flower form, color and structures of the newcultivar, showing the colors as true as it is reasonably possible toobtain in colored reproductions of this type. Colors in the photographsmay differ slightly from the color values cited in the detailedbotanical description, which more accurately describe the actual colorsof the new Euphorbia.

The first photograph shows a side perspective view of a typicalflowering plant of ‘Atlas’ compared to ‘Themis’ grown in 11 cm pots.

The second photograph is a close-up of the young and older floral cymes.

DETAILED BOTANICAL DESCRIPTION

In the following description, color references are made to The RoyalHorticultural Society Colour Chart, 4^(th) edition, where general termsof ordinary dictionary significance are used. Plants are grown undergreenhouse conditions. Plants used for this description were grown forabout 17 weeks after cutting and produced in 11 cm pots. Other pot sizescan be used and the plants are intended for indoor use or as a beddingplant in temperature climates while it is a perennial garden plant intropical and subtropical areas.

Botanical classification: Euphorbia lophogona×E. milii ‘Atlas’.Euphorbiaceae, Spurge family. Common English name: Crown of Thorns.

Parentage:

Female parent.—Unnamed seedling plant Euphorbia lophogona.

Male parent.—Unnamed seedling plant Euphorbia milii.

Propagation:

Type cutting: Terminal vegetative cuttings taken from plants kept in thevegetative stage by shading and high temperatures (25 C.).

Time to initiate roots: About 10 to 14 days at 18 to 21 C. in tunnels ina greenhouse.

Root description: Fine, well branched.

PLANT DESCRIPTION

Form: Perennial plant with upright, cylindrical plant habit. Flowers incymes with cyathia subtended by colored bracts. Freely branching withabout 8 lateral flowering branches forming at every node; dense andbushy. Stems are square to pentagonal with ridges about 10 mm thick atbasis. By each node appears double, vertically flat, rather stiff thorns1 large, 12 mm; 1 smaller, 5 mm. Young thorns are yellow-green: 151A;while the older ones becomes stiffer and changes color to gray (199B).

Crop time: After rooting, about 16-18 weeks are required to producefinished flowering plants in 11 cm pots.

Plant height (soil level to top of plant plane): About 18 cm. Width: 18cm.

Vigor: Moderately vigorous growth rate.

FOLIAGE DESCRIPTION

Leaves alternate, single, obovate shape, margin entire. Length: 7 cm.Width: About 20 mm. Apex: acute. Base: cuneate to almost decussate.Texture: smooth, waxy, dull., glabrous. Color: Young foliage, upper andlower surfaces: 137B and 146C, yellow-green. Mature foliage, upper andlower surfaces: 139C and 146C respectively. Venation, 139B.

FLOWER DESCRIPTION

Flower arrangement and shape: Floral arrangements composed of cymes. Theflowers (cyathia) are starkly reduced so only a ring of 5 glands and thereproductive organs are present. Subtending the cyathia are two coloredbracts. The flowers are further complicated by the unique feature offunnel shaped floral buds appearing at the base of the bracts in two ormore layers.

Natural flowering season: Continuous throughout the spring and summer insubtropical and tropical regions. In colder climates season can beextended by greenhouse production with high temperatures andsupplementary irradiance.

Flower longevity on the plant: 5 to 9 weeks; longevity of individualflowers is highly dependent on temperature and light conditions. Bractsturn green with age. Entire cymes drop after withering.

Inflorescence size: Diameter: About 4-5 cm, height: 10 cm.

Flowers: 3 mm diameter, Bracts: overlapping at base, ovoid to invertedcordate, approximately 10 mm in length by 14 mm in width, color from158B, yellow-white at base and center, Margins 54C, red.

Glands: 5 from N25A shiny orange to 151B yellow-green duringdevelopment.

Anthers: Appear after flowers mature; stamen colors: 186C gray-purple to165B gray-yellow, and pollen 15A, yellow-orange,

Pistil and stigma: Appear before cyathia mature; color 1C,greenish-yellow.

Peduncle: Strength: strong. Length: About 7 cm. Diameter: About 2 mm.Color: 177A, gray-orange.

Pedicels: 1 cm long, 2 mm thick strong color: 177C, gray-orange.

Weather tolerance: Plants of the new Euphorbia have exhibited goodtolerance to draught, rain and wind, however flowering may cease duringcold and dark periods (<15 C.).

Pest tolerance: Plants of the new Euphorbia have exhibited goodtolerance to following fungi: Mildew, and Thivaliopsis. Also they appearto be less infected by Thrips (Franklinellea).

I claim:
 1. A new and distinct cultivar of Euphorbia plant named‘Atlas’, as illustrated and described herein.